The Milwaukee 1/2 in. Drive 9/16 in. SAE 6 Point Standard Socket with FOUR FLAT Sides was designed from the ground up to be part of the most versatile socket family. The 1/2 in. drive sockets feature an innovative design with four parallel flat sides， which deter rolling and are wrench compatible. This standard socket has been optimized geometry to reduce bolt rounding and stripping. Milwaukee backs their 1/2 in. Drive SAE Sockets with a lifetime guarantee.